tracing: fix section mismatch in trace_hw_branches.c

The function bts_trace_init() references a variable
bts_hotcpu_notifier which is marked
as __cpuinitdata. Thus causes section mismatch. This patch fixes it.

   LD      kernel/trace/built-in.o
 WARNING: kernel/trace/built-in.o(.text+0xc90c): Section mismatch in
 reference from the function bts_trace_init() to the variable
 .cpuinit.data:bts_hotcpu_notifier
 The function bts_trace_init() references
 the variable __cpuinitdata bts_hotcpu_notifier.
 This is often because bts_trace_init lacks a __cpuinitdata
 annotation or the annotation of bts_hotcpu_notifier is wrong.

 WARNING: kernel/trace/built-in.o(.text+0xc92a): Section mismatch in
 reference from the function bts_trace_reset() to the variable
 .cpuinit.data:bts_hotcpu_notifier
 The function bts_trace_reset() references
 the variable __cpuinitdata bts_hotcpu_notifier.
 This is often because bts_trace_reset lacks a __cpuinitdata
 annotation or the annotation of bts_hotcpu_notifier is wrong.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Cc: markus.t.metzger@gmail.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>